Prognostic value of malnutrition assessed by Controlling Nutritional Status score for long-term mortality in patients with acute heart failure

Background The prognostic value of nutritional status is poorly understood and evidence-based nutritional assessment indices are required in acute heart failure (AHF). We investigated the prognostic value of malnutrition assessed by the Controlling Nutritional Status (CONUT) score (range 0–12, higher = worse, consisting of serum albumin, cholesterol and lymphocytes) in AHF patients. Methods The CONUT score was measured on admission in 635 consecutive AHF patients. The primary outcome was all-cause death. Results Median CONUT score was 3 (interquartile range 2 to 5). During the median follow-up of 324 days, CONUT score was independently associated with death (HR 1.26, 95% CI 1.11–1.42, P < 0.001) after adjustment for confounders in a multivariate Cox model. The CONUT score demonstrated the best C-statistic for predicting death (0.71) among other common nutritional markers in HF. Furthermore, addition of the CONUT score to an established risk prediction model from the Organized Program to Initiate Lifesaving Treatment in Hospitalized Patients with Heart Failure study significantly increased the C-statistic from 0.75 to 0.77 (P = 0.02). The net reclassification improvement afforded by CONUT score was 21% for all-cause death, 27% for survival and 49% overall (P < 0.001). Conclusion Malnutrition assessed by the CONUT score on admission was an independent determinant of long-term death in AHF, and its prognostic value outweighed that of other nutritional indices. Moreover, addition of the score to the existing risk prediction model significantly increased the predictive ability for death, indicating beneficial clinical application of the CONUT score in AHF patients.